Snow ski and edge

ABSTRACT

A ski in which the metal edges extending longitudinally along the sides of the bottom running surface are provided with a thin layer of hard carbide particles of a size between -100 mesh and +15 microns bonded to the lateral sides thereof having the inherent roughness and abrasive characteristics of such a layer of particles to enhance performance of the ski and its holding ability on icy surfaces. The carbide particles are preferably tungsten carbide, which may be flame sprayed onto the edge in the form of a fused aggregate containing a matrix.

United States Patent [191 Stugger et al.

[ 1 Nov. 11, 1975 1 1 SNOW SKI AND EDGE 22 Filed: June 21,1974

21 App]. No.: 481,942

[52] US. Cl 280/l1.13 E [51] Int. Cl. A63C 5/04 [58] Field ofSearch ..280/11.13 E, 11.13 .1,

11.13 V, 280/11.13 N, 11.13 P, 11.13 Q; 117/105.2,106 C, 46 F5 [56] References Cited UNITED STATES PATENTS 2.964420 12/1960 Poorman et a1. 117/1052 Primm'y Examiner-David Schonberg Assistant E.\'utninerDavid M. Mitchell Attorney, Agent, or Firm-Burgess. Dinklage & Sprung [57] ABSTRACT A ski in which the metal edges extending longitudinally along the sides of the bottom running surface are provided with a thin layer of hard carbide particles of a size between 100 mesh and +15 microns bonded to the lateral sides thereof having the inherent roughness and abrasive characteristics of such a layer of particles to enhance performance of the ski and its holding ability on icy surfaces. The carbide particles are preferably tungsten carbide, which may be flame sprayed onto the edge in the form of a fused aggregate containing a matrix.

8 Claims, 2 Drawing Figures 3,419.415 12/1968 Dittrich 117/46 FS 3.617.358 11/1971 Dittrich 117/1051 3.719.519 3/1973 Perugini 117/1052 FOREIGN PATENTS OR APPLICATIONS 1,563,297 3/1969 France 280/1 1.13 E

U.S. Patent Nov. 11, 1975 I 2 l.- l: r

posite construction, having fiber glass and/or metal structural bottom and top portions separated by a core of wood, foam, honeycomb metal, or the like. The bottom running surface or sole is generally provided with a layer of plastic material, such as polyethylene, to insure free running and prevent sticking on the snow, and longitudinal metal edges extend along the sides of the running bottom surface to help the skier carve his turns and in order to hold and check the skiers speed on hard packed and icy surfaces. These metal edges may be in the form of edge segments, continuous metal edges, or what is known as cracked edges, i.e., edges having transverse cracks spaced therealong in order to increase their flexibility. Ski edges, generally, have a right angular profile to provide a cutting edge at the apex.

While the edges are normally made of hardened steel, they still require frequent sharpening by filing when hard-packed or icy conditions are encountered, and depend on the maintenance of the sharp apex for their holding ability.

Even, however, a well-sharpened ski does not have all that could be desired with respect to holding ability as the skier attempts to carve a turn or check when icy conditions or icy patches are encountered.

As the slopes have become more crowded as skiing has become more popular, hard-packed and icy conditions become more prevalent, and in many areas of the country, these conditions have become the rule more than the exception, and have caused a great deal of dif: ficulty to all but the most expert of skiers.

Proposals have been made to provide skis with greater holding and carving ability under these conditions by providing serrations, teeth, or other special edge configurations for the ski.

None of these proposals, however, has proven satisfactory, as, in general, the providing of the ski edge with serrations, saw teeth, or other cutting configurations has caused excessive drag during regular skiing and severely impaired the performance of the ski with respect to its normal tracking and turning characteristics.

One object of this invention is an improved construction for a ski and ski edge, which overcomes the abovementioned disadvantages and which provides superior holding and carving ability for the ski, without sacrifree, and in many cases enhancement of the other overall performance characteristics of the ski.

A further object of this invention is an improved ski and ski edge, which maintains its holding and carving ability without the conventionally required sharpening.

These and still further objects will become apparent from the following description read in conjunction with the drawings, in which FIG. 1 is a perspective view of an embodiment of a ski in accordance with the invention; and

FIG. 2 is a cross-section of the ski shown in FIG. 1.

In accordance with the invention, a thin layer of hard carbide particles are bonded to a lateral side of at least one of the metal edges of the ski and extend along a substantial portion of the length thereof.

Referring to the embodiment shown in the drawings, 1 designates a ski which may be of any conventional construction and which is provided with the bottom running surface or sole 2, having the longitudinal metal edges 3 and 4, respectively. In accordance with the invention, the lateral sides of the edges 3 and 4 are provided with a thin layer of hard carbide particles 5 and 6 bonded thereto. While, preferably, both of the edges 3 and 4 are provided with the thin layer of hard carbide particles, within the broadest concept of the invention, it is only necessary to provide one of these edges with the layer of hard carbide particles, in which case, the edge so provided is utilized as the inside edge of the ski.

While the entire length of the edge from the tail to the tip may be provided with the layer of carbide particles, the layer of carbide particles need not extend over the entire length of the edge, and thus, for example, the layer of the hard carbide particles need only extend over a major portion of the ski between the tip and the tail, or within the broadest concept of the invention, over any other portion where it is desired to give the ski the greatest holding ability.

While in the embodiment shown, the ski is a fiber glass ski, having an upper fiber glass plate 7, a lower fiber glass plate 8, and a polyethylene sole 9 bonded to the lower plate 8, with a core 10 and protective plastic sides 11 and 12, the ski may be of any known or conventional construction. While the metal edges 3 and 4 as shown are continuous metal edges bonded to the ski in the conventional manner, the edges may have any other conventional form, such as segmented or cracked" edges.

As the hard carbide particles, any of the known hard carbide particles, such as for example, tungsten carbide, titanium carbide, tantalum carbide, chromium carbide, boron carbide, vanadium carbide, or zirconium carbide, may be used, though tungsten carbide has been found preferable.

The layer of the carbide particles should generally be of a thickness of 1-10, and preferably 3-7, mils.

While the carbide particles may be bonded to the laterial side of the edge to form the thin layer in any known or conventional manner, as for example, by brazing or welding, it has been found preferable to apply the layer of particles utilizing a spray process.

For this purpose, the carbide particles, such as the tungsten carbide particles, are preferably in the form of a fused carbide aggregate containing the carbide itself in about 6-25, and preferably 9-14, percent by weight of a matrix, preferably nickel, or most preferably cobalt. The fused aggregate particles should have a particle size between about mesh (US. Standard Screen Size) and 15 microns, with the aggregate granules made up of fine carbide particles of, for example, a particle size of -325 mesh to as small as a micron or less, bound intimately together by the matrix material and formed, for example, by casting or sintering.

The carbide particles may be sharp angular particles, and rather than being in the form of a fused aggregate, the individual particles may be in the form of individual pure carbide particles clad with the nickel or cobalt matrix metal.

The fused carbide aggregate particles may be applied to the edge in the form of a layer by the known sprayweld process, in which a layer of the particles is initially deposited by flame spraying and thereafter fused in place. When applied by this process, the particles may be admixed with a conventional spray-weld alloy, i.e., one containing a fluxing element, such as boron, or the matrix material itself of the fused aggregate particles may be in the form of a conventional spray-weld alloy containing the fluxing element.

The particles may be applied to the edge in any other known manner prior to the fusion operation. Thus, the same may be simply loosely distributed on the edge and fused in place, or applied to the edge in a binding agent, such as an organic binder or shellac, which will burn away or volatilize during the fusion operation.

The particles may also be applied by the detonation spraying process, as for example, is described in US. Pat. No. 2,714,536.

When the layer of the hard carbide particles are ap plied by brazing, welding or spray-welding, which re: quires a heating of the edge to a high temperature at which fusion of the particles and bonding to the edge occurs, the layer must be applied to the edge before it is attached to the ski, and after the application, the edge is attached to the ski in the conventional manner. For, this purpose, a large number of edges may be stacked and simultaneously coated with the layer of the hard carbide particles.

In accordance with a preferred embodiment of the invention, the layer of the hard carbide particles are ap plied by flame spraying without a subsequent fusion or welding operation, i.e., what is known in the art as the cold process, in that the work piece is not unduly or deleteriously heated.

For this purpose, it has been found preferable to ef: fect the flame spraying with a plasma type flame spray gun, and most preferably one which is operated at high velocity.

The lateral surface of the edge to be coated, in accordance with the invention, is first cleaned and prepared in the conventional manner for flame spraying, as for example, by grit blasting, mechanically roughening, thread cutting, serrating, or the like.

It is also possible to initially spray a bonding coat, as for example, one formed from a nickel-aluminum composite powder, as described in US. Pat. No. 3,254,907, or to mix the carbide particles being sprayed with such a nickel-aluminum bonding powder.

The applied layer of the hard carbide particles should have a Rockwell hardness of at least C 60, and preferably at least C 75 and will, of course, have the inherent roughness and abrasive characteristics of such a layer of particles.

In use, the ski with the new edge, in accordance with the invention, holds tenaciously on ice when the skier checks and attempts to carve turns, and yet does not interfere with the normal free running or other desirable characteristics of the ski, and in fact, seems to en; hance the other performing cha acteristics, such as the turning ability and stability of the ski, without interfering with its free running. The edge is extremely longlasting and durable, does not require the ordinary sharpening, and may be considered self-sharpening. If necessary, the edge may be touched up or dressed with a diamond stone or carbide containing file or abrasive wheel.

The following example is given to illustrate the appli: cation of the layer of carbide particles, in accordance with the invention, by the cold" flame spray process,

which allows the application of the coating not only to EXAMPLE A pair of conventional, commercially available snow skis of fiber glass construction with continuous metal edges and a length of 180 cmwere clamped together with their soles mating, so that the edges of both skis could be sprayed simultaneously.

The lateral sides of the edges were cleaned with emery cloth and grit blasted with a coarse. angular steel grit of a mesh size S.A.E. G 25, using compressed air at a pressure of 100 pounds per square inch witha inch nozzle. The grit blasting was effected to provide a surface roughness of at least 200 microinches as measured with a profilometer.

A tungstencarbide powder in the form of fused aggregate granules containing 12 percent cobalt as a rnatrix and of a size between -325 mesh and +15 microns.

was used. The tungsten carbide powder was sprayed onto the lateral edges of the skis, using a plasma flame spray gun as manufactured by Metco, Inc, of Westbury,

Long Island, and sold under the designation 3 MB Plasma Flame Spray Gun. A Metco GP nozzle was used with a primary argon flow of 160 standard cubic feet per hour and a secondary helium gas flow of 144 standard cubic feet per hour. The gun wasoperated with an arc voltage of to volts at 500 amps. The powder was fed through the gun at a rate of 6-9 pounds per hour, and spraying was effected at a distance of between 2 /2 and 3% inches, with a deposit efficiency of 70 percent.

A layer thickness of between about 4 and 5' mils of: the carbide particles was deposited along the lateral edges of the skis.

In use, the skis showed greatly superior holding and carving power on icy and hard-packed surfaces, as

compared to an identical pair of the same type of skis with a sharpened but non-coated edge which superiority may be attributed to the inherent roughness and abrasive characteristics of the layer of particles. The I skis additionally showed improved stability and ap-- peared to react under skiing conditions as a longer pair. of skis and yet turned easily. The free-running characteristics of the skis were not impaired, nor were any of i 1. In a snow ski having a running bottom surface with longitudinal metal edges, the improvement which comprises a thin layer of l-lO mils thickness'ofhard carbide particles of a particle size between about mesh and +15 microns bonded 'to a lateral side of at least one of the metal edges and extending along a sub:

stantial portion of the length thereof, said layer being characterized by the inherent roughness and abrasive characteristics of such a layer of particles.

2. Improvement according to claim 1, in which said layer of hard carbide particles has a thickness of be:

tween about 3 and 7 mils.

3. Improvement according to claim 1, in which said layer of hard carbide particles is a layer of hard tung- 6. Improvement according to claim 1, in which the lateral sides of both edges of the ski have said thin layer of hard carbide particles bonded thereto.

7. A metal ski edge having a thin layer of l-l0 mils thickness of hard carbide particles of a particle size between -l00 mesh and +15 microns bonded to the lateral side thereof and extending along a substantial portion of the length thereof, said layer being characterized by the inherent roughness and abrasive characteristics of such a layer of particles.

8. Edge according to claim 7, in which said hard carbide particles are tungsten carbide particles flame sprayed to the edge. 

1. In a snow ski having a running bottom surface with longitudinal metal edges, the improvement which comprises a thin layer of 1-10 mils thickness of hard carbide particles of a particle size between about -100 mesh and +15 microns bonded to a lateral side of at least one of the metal edges and extending along a substantial portion of the length thereof, said layer being characterized by the inherent roughness and abrasive characteristics of such a layer of particles.
 2. Improvement according to claim 1, in which said layer of hard carbide particles has a thickness of between about 3 and 7 mils.
 3. Improvement according to claim 1, in which said layer of hard carbide particles is a layer of hard tungsten carbide-containing particles.
 4. Improvement according to claim 1, in which said thin layer is a flame sprayed layer of hard carbide particles in the form of fused carbide aggregates of a particle size between about -100 mesh and +15 microns, and containing about 6 to 25 percent by weight of a matrix selected from the group consisting of nickel and cobalt matrices.
 5. Improvement according to claim 4, in which said fused carbide aggregate is a fused tungsten carbide cobalt matrix aggregate containing about 9 to 14 percent by weight of cobalt.
 6. Improvement according to claim 1, in which the lateral sides of both edges of the ski have said thin layer of hard carbide partIcles bonded thereto.
 7. A metal ski edge having a thin layer of 1-10 mils thickness of hard carbide particles of a particle size between -100 mesh and +15 microns bonded to the lateral side thereof and extending along a substantial portion of the length thereof, said layer being characterized by the inherent roughness and abrasive characteristics of such a layer of particles.
 8. Edge according to claim 7, in which said hard carbide particles are tungsten carbide particles flame sprayed to the edge. 